Dental component and a dental implant

ABSTRACT

The invention relates to a dental component, such as an abutment, an abutment replica, an abutment blank, a customized abutment, a scan abutment, a digital transfer coping, an impression pick-up element, a healing cap or a driver, comprises a first indexing element and at least two second indexing elements having apical ends located apically of the apical end of said first indexing element. The invention also relates to a dental implant which comprises a dental component having first and second indexing elements and a fixture having third and fourth indexing elements, wherein the first and third indexing elements can only engage with each other after the second and fourth indexing elements have engaged with each other. The invention also relates to a fixture.

RELATED APPLICATIONS

This is a continuation application U.S. application Ser. No. 13/613,118,filed on Sep. 13, 2012, which claims the benefit of and priority to EPApplication Ser No. 11181242.6, filed on Sep. 14, 2011 and U.S.Provisional Patent Application Ser. No. 61/534,521, filed on Sep. 14,2011, which are herein incorporated by reference for all purposes.

TECHNICAL FIELD

The present invention relates to a dental component comprising a fixtureengagement portion for engaging the dental component with a dentalfixture adapted to be inserted into a jawbone or for engaging the dentalcomponent with a fixture replica. The invention also relates to a dentalimplant comprising a dental fixture adapted to be inserted into ajawbone and a dental component connectible to the dental fixture. Theinvention also relates to such a dental fixture.

BACKGROUND OF THE INVENTION

Dental implant systems are widely used for replacing damaged or lostnatural teeth. In such systems, a dental fixture is placed in thejawbone of a patient in order to replace the natural tooth root. Anabutment structure comprising one or several parts may then be attachedto the fixture in order to build up a core for the part of theprosthetic tooth protruding from the bone tissue, through the softgingival tissue and into the mouth of the patient. On said abutment, theprosthesis or crown may finally be seated.

The final prosthesis should be sized and configured so as to naturallyfit with the remaining teeth of the patient, both for functionality andaesthetics. To this end a dental technician may try out a properprosthesis for the individual patient, using a model of the jaw of thepatient, said model including the fixture. The dental technician mayalso digitally work out a proper prosthesis based on a digital model ofthe jaw of the patient either with a fixture already installed or priorto such installation. The dental technician may also modify apre-fabricated abutment to match the contour of the soft gingivaltissue.

There are various fixture configurations. For instance, a fixture mayhave a flat topped coronal head portion, which may be installed in anyrotational position relative to the jawbone. Another type of fixtureconfiguration is a fixture having a sloped coronal end portion, such asdisclosed in U.S. Pat. No. 6,655,961, in which the length of the fixtureis greater on the lingual side than on the buccal side in order to matchthe contour of the jawbone.

Similarly, to the above described fixture/jawbone-interface, for asuperstructure, such as an abutment, there may be anabutment/fixture-interface in which the abutment should only bepositioned in one way relative to the fixture, e.g. an abutment having asloped portion matching the sloped head portion of a fixture. This isone type of asymmetrical superstructure, in which the asymmetricalfeature should be positioned in a desired rotational relationship toeither or both of the fixture and the jawbone with surrounding teeth.Thus, with regard to these interfaces, it would be desirable to ensurethat the dentist connects the superstructure with a correct rotationalorientation relative to certain fixtures or jawbone features. Also forpatient-specific or customized superstructures, such as a customizedabutment, such superstructure may often be made with a certain intendedrotational orientation relative to the fixture and surrounding contours.Thus, also in these cases it would be desirable to ensure that thedentist connects the superstructure with a correct rotationalorientation relative to the fixture and other features in the oralcavity.

When making an abutment and a prosthetic tooth, the dental technicianhas thus taken the contours and locations of surrounding tissue andadjacent teeth into account. A system used at present time to manoeuvrethe rotational position of asymmetrical superstructures is to provide atwo-part abutment having a centrally positioned threaded screw, whichmates with an internally threaded bore of the fixture, and a sleevewhich is given the asymmetrical patient specific features at its coronalend which are needed to be a suitable basis for the prosthetic tooth.The sleeve may be rotated into the correct position in a seating of theinternal bore of the fixture and be fixed therein by the screw. Theseating in the fixture and the apical end of the sleeve of the abutmentare, axially symmetrical to ensure that a correct final position may beachieved. The correct positioning is this way depending on the dentist'sability to visually verify the result.

The dentist receives the abutment and prosthetic tooth either as oneintegral unit or as separate parts to be assembled in the oral cavity ofthe patient. Often, the dentist who receives the abutment and theprosthetic tooth should understand how the abutment should berotationally oriented relative to the fixture in order to obtain thealignment as intended by the dental technician. Nevertheless, it maysometimes be difficult for the dentist to see which is the correctorientation and, of course, there may be a risk of the dentist simplyoverlooking or ignoring the correct rotational orientation of theabutment relative to the fixture.

There have been proposed different solutions which only allow theabutment to be placed in a single rotational orientation relative to thefixture. Nevertheless, dentists may still experience difficulties infinding the correct orientation, and may have to rotate the abutment fora while before it falls into place.

An object of the invention is to enable the dentists to find a desiredrotational orientation of a dental component, such as an abutment,relative to a fixture more easily than what is offered by the currentlyavailable solutions.

These and other objectives, which will become apparent in the following,are achieved by the dental component and the dental implant as definedin the accompanied claims.

SUMMARY OF THE INVENTION

The present invention is based on the insight that when connecting adental component to a dental fixture, two or more leading indexingelements may be used for guiding the dental component into a desiredrotational position relative to the fixture before one or moresubsequent trailing indexing elements are engaged to form the finalrotational lock.

According to a first aspect of the invention, a dental component isprovided. The dental component comprises a fixture engagement portionfor engaging the dental component with a dental fixture adapted to beinserted into a jawbone or for engaging the dental component with afixture replica, the fixture engagement portion having a geometricalcentral axis and being provided with at least one radially projectingfirst indexing element having an apical end, and at least two radiallyprojecting second indexing elements, each one having an apical endlocated apically of the apical end of said first indexing element.

This has the effect that when the dental component is to be connectedwith the fixture and thus moved towards the fixture, the at least twosecond indexing elements will be the first to mate with the fixture. Inthis way, the location finding function of the indexing elements will beconcentrated to only part of the circumference of the fixture engagementportion. The dentist will experience a more distinct perception whensaid at least two second indexing elements fall into place with acorresponding receiving portion of the fixture, compared to if allindexing elements around the circumference of the fixture engagementportion were to connect simultaneously as in the prior art.

According to at least one example embodiment, said at least two secondindexing elements are asymmetrically distributed along the circumferenceof the fixture engagement portion. Since the second indexing elementsare asymmetrically distributed along the circumference of the fixtureengagement portion, a component/fixture interface may, if desired, beprovided in which the second indexing elements only have one correctrotational position, thereby avoiding that the dentist connects thedental component to the fixture in an incorrect rotational orientation.

According to at least one example embodiment, said at least one firstindexing element is circumferentially separated from any one of said atleast two second indexing elements This means that said first indexingelement is located at a different position along the circumference ofthe fixture engagement portion than any one of the second indexingelements. In other words, a radius drawn from the geometrical centralaxis to the first indexing element extends in a different direction fromsaid axis than any radii drawn from said axis to the second indexingelements.

Suitably, the apical ends of said at least two second indexing elementsare arranged at substantially the same level in the apical-coronaldirection.

Having at least two second indexing elements with a leading functionachieves a stabilizing or balancing effect. If the dental component isintended to be connected to a dental fixture allowing the dentalcomponent to be arranged in any one of a plurality of rotationalorientations, it can be connected in any one of those rotationalorientations. However, when the dentist wishes to connect the dentalcomponent to a dental fixture only allowing the dental component to beconnected in a single specified rotational orientation, the advantage ofhaving two leading second indexing elements will become apparent. Ifthere would have been only one leading second indexing element it couldhave incorrectly be received by anyone of the mating (suitably indented)indexing elements of the fixture, before the dentist annoyed realizesthe incorrect rotational orientation because of the trailing firstindexing element does not find a mating indexing element. By having twoleading second indexing elements, only when both have been aligned withthe correct indexing elements of the fixture will the mating bepossible. As long as one of the second indexing elements rests on asurrounding wall portion (e.g. a shelf) in the fixture, it prevents thedental component from moving further apically, and thus also preventsthe other second indexing element from dropping into an incorrectindentation in the fixture.

According to at least one example embodiment, the axial extension of theindexing elements is such that the first indexing element and the secondindexing elements are intersected by a common geometrical plane which isperpendicular to the central axis of the fixture engagement portion.Thus, apart from having the apical ends located at different apicalpositions, the first and second indexing elements may have substantiallythe same configuration which may be advantageous from a manufacturingperspective. Furthermore, although the dental component may only haveone specific rotational orientation in one type of fixture, it could beallowed to have other rotational orientations in other types offixtures, in which case the mating indexing elements in the fixturecould receive any one of the first and second indexing elements of thedental component. Such freedom of choice would be more complicated ifthe first and second indexing elements are completely separated in theaxial direction of the fixture engagement portion.

According to at least one example embodiment, said at least one radiallyprojecting first indexing elements comprises at least two radiallyprojecting first indexing elements. Thus, in such case, there will be atleast two leading (second) indexing elements which will facilitatefinding the correct location and at least two trailing (first) indexingelements which will provide and/or complement a rotational locking ofthe dental component to the fixture.

According to at least one example embodiment, said at least two radiallyprojecting second indexing elements are arranged as at least threeradially projecting second indexing elements, interposed between two ofsaid first indexing elements, wherein each one of said at least threesecond indexing elements has an apical end which is located apically ofthe apical ends of said first indexing elements. This provides increasedstability when the dentist intends to find of the correct rotationalorientation of the dental component in the fixture.

Thus, it should be understood that said at least two second indexingelement may, for instance, be three, four or more indexing elements.

According to at least one example embodiment, a radius from said centralaxis to the centre of one of said at least two second indexing elementsand a radius from said central axis to the centre of said first indexingelement form a first angle, wherein a radius from said central axis toanother one of said at least two second indexing elements and saidradius from said central axis to the centre of said first indexingelement form a second angle, wherein said second angle is different fromsaid first angle and from any angle being a multiple of said firstangle. A multiple is the product of a quantity by an integer. In otherwords, φ≠nθ, where θ is the first angle, φ is the second angle and n isa positive integer.

Since said second angle is different from said first angle (and anymultiple thereof) an asymmetry is achieved. Only by rotating the dentalcomponent a full 360° can the first and second indexing elements obtainthe same positional distribution relative to the surroundingenvironment. This is in contrast to a symmetrical distribution ofindexing elements; for instance, a component having four symmetricallydistributed indexing elements can be rotated 90° to obtain the samepositional distribution as before relative to the surroundingenvironment. The asymmetry provided by this example embodiment reducesthe risk of the second indexing elements getting caught in incorrectindexing elements in the fixture.

The asymmetrical distribution of the indexing elements comprising atleast two first and at least two second indexing elements is reflectedin at least one example embodiment, according to which the spacingbetween said two second indexing elements is different from the spacingbetween any two of said first indexing elements. The two second indexingelements do not have to lie next to each other. There may be one or morefirst indexing elements which are placed between said two secondindexing element. Also, if there are more than two second indexingelements, some of them may be spaced at the same distance as the spacingbetween first indexing elements, as long as there can be identified onepair of second indexing elements having a different spacing. Theadvantage of this asymmetry will now be explained. Assuming the dentalcomponent is to be connected to a dental fixture having correspondingmating third and fourth indexing elements, wherein the third indexingelements are designated to mate with the first indexing elements of thedental component while the fourth indexing elements are designated tomate with the second indexing elements of the dental component, thenthere will be only one correct rotational orientation. Since the apicalends of the second indexing elements will be leading and be the first toform contact with the dental fixture, because of the distinct spacingbetween said pair of second indexing elements these cannot inadvertentlybe mated with the differently spaced third indexing elements.

According to at least one example embodiment said at least one firstindexing element and said at least two second indexing elements togetherform a series of indexing elements which comprises the following twoclassifications:

Classification A: Indexing elements which are separated from theirneighboring indexing elements by no more than a first distance.

Classification B: Indexing elements that are separated from theirneighboring indexing elements by more than said first distance, whereinat least one of the second indexing elements is present inClassification A.

For instance, indexing elements under Classification B may bedistributed around the fixture engagement portion at intervals of anangle θ, and an indexing element under Classification A would beinterposed between the other indexing elements. As an example, there maybe six indexing elements which are spaced at 60° intervals from oneindexing element to the next, and a seventh indexing element which islocated in-between two of the other six elements (i.e. spaced at 30°from those two indexing elements). Said six regularly distributedindexing elements could go under classification B, however, out of thosesix indexing elements, the two indexing elements neighboring the seventhindexing element could also go under Classification A (as would theseventh indexing element). Thus, at least the extra seventh indexingelement is in the form of one of said at least one second indexingelements having an apical end located apically of the apical ends of thefirst indexing element. However, if the mating fixture has sevenreceiving recesses of substantially equal dimensions, the seventhindexing element could incorrectly enter anyone of those recesses.Therefore, in order to make sure that there is only one rotationalorientation in which the dental component can mate with the fixture, atleast one of the other six indexing elements should also be a “second”indexing element having an apical end located apically of the apicalends of the first indexing elements. Advantageously, although notnecessarily, the two indexing elements which neighbor the seventhindexing element may be “second” indexing elements having an apical endlocated apically of the apical ends of the first indexing elements.

The above example of the six equidistantly spaced indexing elements, anda seventh extra indexing element is encompassed by at least thefollowing example embodiments. According to at least one exampleembodiment, said at least one first indexing element and said at leasttwo second indexing elements add up to N number of indexing elements,wherein N−1 of the indexing elements are equidistantly distributedaround the fixture engagement portion, and wherein the remainingindexing element (the N:th indexing element) is interposed between twoof said equidistantly distributed N−1 indexing elements, wherein theremaining indexing element is one of said at least two second indexingelements. At least one of said equidistantly distributed N−1 indexingelements is also a second indexing element having its apical end locatedapically of the other equidistantly distributed (first) indexingelements. According to at least one example embodiment, one or both ofthe indexing elements neighboring said remaining indexing element is/arealso a second indexing element.

According to at least one example embodiment, following thecircumferential direction of the fixture engagement portion, said atleast two second indexing elements are interposed between two of saidfirst indexing elements. Thus, there is at least one geometrical planewhich is perpendicular to the central axis of the fixture engagementportion and which extends through the first indexing elements as well asthrough the second indexing elements. The coronal extension of thesecond indexing elements may suitably be to the same axial level as thecoronal extension of the first indexing elements. Alternatively, thecoronal extension of the second indexing elements may be longer orshorter than the coronal extension of the first indexing elements.

In order for the second indexing elements to perform a guiding orleading function and the trailing first indexing element to follow witha final rotational locking function, it is not necessary for the secondindexing element to be interposed between two first indexing elements.The entire second indexing element may be located apically of the apicalend of the at least one first indexing element. For instance, the secondindexing elements may be in the form of short protrusions at an apicalsub-portion of the fixture engagement portion, while the apical end ofthe at least one first indexing element is located coronally thereof, ata coronal sub-portion of the fixture engagement portion. Once the secondindexing elements have engaged with matching indexing elements in thefixture, the dental component will continue its relative movementtowards the fixture and eventually the at least one first indexingelement will also engage a matching indexing element (it is assumed thatthe indexing elements in the fixture receiving the leading secondindexing elements are long enough to allow said continued motion of thedental component). Thus, in view of the above discussion, according toat least one example embodiment, there is at least one geometrical planewhich is perpendicular to the central axis of the fixture engagementportion and which is located apically of the at least one first indexingelement and coronally of the second indexing elements.

According to at least one example embodiment, the fixture engagementportion of the dental component comprises a cylindrical surface fromwhich said at least one first indexing element and said at least twosecond indexing elements project radially. This is advantageous from amanufacturing point of view. However, it is conceivable to have theindexing elements project radially from other surfaces as well, e.g.from a tapered surface.

According to at least one example embodiment, the number of firstindexing elements is greater than the number of second indexingelements. While the number of second indexing elements may suitably betwo or three, the trailing first indexing elements which complete therotational locking may suitably be more for increased strength. This maybe particularly advantageous if the dental component is a driver,wherein the indexing elements are adapted to transfer a torque to thedental fixture when driving it into the jawbone.

According to at least one example embodiment, the apical end of at leastone of said at least two second indexing elements is provided with achamfer. When the fixture engagement portion of the dental component isinserted into the fixture, the dentist will rotate the dental componentin order to align the indexing elements of the dental component withmating indexing elements of the fixture. The provision of the two secondindexing elements, at least partly reduces the risk of one of thoseindexing elements engaging with the wrong indexing element in thefixture. Nevertheless, if for instance the dentist tilts the dentalcomponent when trying to connect it to the dental fixture, a secondindexing element might accidently drops into the wrong indexing element(such as a groove) in the dental fixture upon rotation of the dentalcomponent, despite the supporting function of the other second indexingelement. In such case, when the dentist continues to apply a rotatingforce onto the dental component the provision of a chamfer on thatsecond indexing element will facilitate lifting that second indexingelement out of the temporary incorrect engagement.

According to at least one example embodiment, each one of said secondindexing elements has a smaller dimension in the circumferential(transverse) direction and/or in the radial (projecting) directioncompared to the dimensions of said at least one first indexing element.This is advantageous if, for instance the dental fixture has equallydimensioned recesses for receiving the indexing elements (projections)of the dental component, because in such case the second indexingelements, which have a smaller dimension (e.g. transverse to thecoronal-apical direction) than the at least one first indexing element,will be received in their receiving recesses with a relatively largeplay (in this example, a large play in the transverse direction). Thesecond indexing elements, having their apical ends located apically ofthe apical end of the at least one first indexing element, will bereceived by their corresponding recess before the trailing firstindexing element is received by its corresponding recess in the fixture.The relatively large play facilitates for the dentist to get the secondindexing elements into engagement with the corresponding recesses in thefixture. Thus, at this stage, when only the second indexing elementshave been engaged, a small rotational movement of the dental componentrelative to the fixture may be possible. However, when the at least onefirst indexing element follows to engage with its corresponding recess,since it is suitably more accurately dimensioned to fit closely in itsrecess, the dental component will become rotationally locked when theone or more first indexing elements have entered in engagement withtheir respective recesses.

According to at least one example embodiment said at least one firstindexing element and said at least one second indexing elements have anelongate extension in the coronal-apical direction. This providesadditional strength to the rotational lock compared to if the radiallyprojecting indexing elements would have a shorter extension.

According to at least one example embodiment, the dental component is acomponent selected from the group consisting of an abutment, an abutmentreplica, an abutment blank, a customized abutment, a scan abutment, adigital transfer coping, an impression pick-up element, a healing capand a driver.

For instance, a customized abutment may have a shape which is adapted tothe contours of the surrounding tissue and teeth of the patient, inwhich case it is advantageous if the dentist can easily fit thecustomized abutment in the intended rotational orientation.

A digital transfer coping having some distinguishing feature indicatingits rotational orientation and being connected to a dental fixture maybe scanned, and a digital file is then sent to an abutment manufacturer.The digital file will contain information about the position andorientation of the distinguishing feature and thus also the position andorientation of the dental fixture.

A driver having a distinctive marking may be used as an indication todetermine if the fixture has been inserted at a desired orientationrelative to the jawbone and other surrounding features in the oralcavity. For instance, the fixture may have a sloping coronal end. Thedriver may be intended to be inserted such that the distinctive markingis aligned with the very top of the sloping end of the fixture. Thus,during rotation of the fixture into the jawbone, the dentist will knowthe rotational orientation of the fixture and its sloping end by lookingat the distinctive marking. It is therefore advantageous if the dentistcan easily fit the driver into the intended position relative to thefixture.

According to a second aspect of the invention, a dental implant isprovided. The dental implant comprises a dental component comprising afixture engagement portion provided with at least one first indexingelement having an apical end, and at least two second indexing elements,each one having an apical end, a dental fixture adapted to be insertedinto a jawbone and comprising a component engagement portion adapted tomate with said fixture engagement portion, the component engagementportion being provided with at least one third indexing element having acoronal end, and at two fourth indexing elements, each one having acoronal end, wherein the apical ends of said at least two secondindexing element are located apically of the apical end of the firstindexing element and/or the coronal ends of said at least two fourthindexing elements are located coronally of the coronal end of the thirdindexing element, wherein the first, second, third and fourth indexingelements are distributed along the circumference of the fixtureengagement portion and the component engagement portion, respectively,in such way that the dental component can only mate in one rotationalorientation with respect to the dental fixture, wherein the firstindexing element is only enabled to mate with the third indexing elementafter said at least two second indexing elements have mated with said atleast two fourth indexing elements.

Thus, the second and fourth indexing elements will act to guide thedental component into a desired rotational orientation relative to thefixture. Once this rotational orientation has been found, and the dentalcomponent is continued to be displaced apically, the first and thirdindexing element will then engage each other to provide a finalrotational stop. While the first and third indexing elements, suitably,form a relatively tight fit in order to reduce the risk of smallrotational movements between the dental component and the dentalfixture, the fit between the second and fourth indexing elements mayadvantageously be provided with a play. This is reflected in at leastone example embodiment, according to which a play (e.g. a lateral playor a radial play) between the first indexing element and the matingthird indexing element is smaller than a play between said at least twosecond indexing element and said at least two mating fourth indexingelement, whereby a tighter fit is provided between the first and thirdindexing elements compared to the fit between the second and fourthindexing elements.

The play between the second and fourth indexing elements makes it easyfor the dentist to find the desired rotational orientation as the secondindexing element will more easily be received by the fourth indexingelement than what would be the case without such a play. The tight fitbetween the first and third indexing elements makes sure that the samerotational position is obtained throughout a multi-step procedure, e.g.making an impression with a dental component (such as a transfer coping)connected to the fixture, making a model based on the impression, makinganother dental component (such as an abutment) based on the model andconnecting the latter dental component to the dental fixture. Apotential rotational error, although small, in each step, may in the endresult in a large rotational error. The tight fit between the first andthird indexing elements reduces the risk of rotational errors in eachstep.

According to at least one example embodiment, said first and secondindexing elements are provided as radial projections which project froma surface of the fixture engagement portion of the dental component, andwherein said third and fourth indexing elements are provided as radialdepressions in a surface of the component engagement portion of thedental fixture. However, it would be conceivable to have it the otherway around, i.e. the projections on the fixture and the depressions inthe dental component. Other mixed alternatives are also conceivable aslong as the second and fourth indexing elements mate before the matingof the first and third indexing elements.

According to at least one example embodiment, said at least one firstindexing element is circumferentially separated from any one of said atleast two second indexing elements, and wherein said at least one thirdindexing element is circumferentially separated from any one of said atleast two fourth indexing elements.

According to at least one example embodiment, said at least two secondindexing elements are asymmetrically distributed along the circumferenceof the fixture engagement portion, and wherein said at least two fourthindexing elements are asymmetrically distributed along the circumferenceof the component engagement portion.

According to at least one example embodiment, a radius from a centralaxis of the fixture engagement portion to the centre of one of said atleast two second indexing elements and a radius from said central axisto the centre of said first indexing element form a first angle, whereina radius from said central axis to another one of said at least twosecond indexing elements and said radius from said central axis to thecentre of said first indexing element form a second angle, wherein saidsecond angle is different from said first angle and from any angle beinga multiple of said first angle.

According to at least one example embodiment, in the dental fixture, aradius from a central axis of the component engagement portion to thecentre of one of said at least two fourth indexing elements and a radiusfrom said central axis to the centre of said third indexing element forma first angle, wherein a radius from said central axis to another one ofsaid at least two fourth indexing elements and said radius from saidcentral axis to the centre of said third indexing element form a secondangle, wherein said second angle is different from said first angle andfrom any angle being a multiple of said first angle.

According to at least one example embodiment, the dental component hasat least two first indexing elements and the dental fixture has at leasttwo mating third indexing elements. According to at least one exampleembodiment, the spacing between the two second indexing elements isdifferent from the spacing between any two of said first indexingelements; and the spacing between said two fourth indexing elements isdifferent from the spacing between any two of said third indexingelements. The two second indexing elements do not have to lie next toeach other; nor do the two fourth indexing elements have to lie next toeach other. There may be one or more first indexing elements which areplaced between said two second indexing elements. Likewise, there may beone or more third indexing elements which are placed between said twofourth indexing elements. Also, if there are more than two secondindexing elements, some of them may be spaced at the same distance asthe spacing between first indexing elements, as long as there can beidentified one pair of second indexing elements having a differentspacing. Likewise, if there are more than two fourth indexing elements,some of them may be spaced at the same distance as the spacing betweenthird indexing elements, as long as there can be identified one pair offourth indexing elements having a different spacing. The advantage ofthis asymmetry has already been explained above in connection with thediscussion of the first aspect of the invention.

According to at least one example embodiment, the fixture engagementportion and the first and second indexing elements of the dentalcomponent are rotatable inside the component engagement portion of thefixture before the second indexing elements have mated the fourthindexing elements. This facilitates the location finding function andreduces the risk of skewing of the dental component relative to thefixture. For instance, the fixture may at its coronal end have aninternal socket defined by a wall portion in which third and fourthindexing elements in the form of radially extending recesses areprovided. The dental component and its first and second indexingelements may be inserted into the socket and rotated. Suitably, thesecond indexing element, may during rotation bear upon a shelf whichcontains said recesses. As the dental component is rotated and thesecond indexing elements moves along the shelf, the second indexingelements will eventually drop into the recesses.

According to at least one example embodiment, the dental component ofthe dental implant according to the second aspect of the invention, is adental component having the features discussed in connection with thefirst aspect of the invention.

According to a third aspect of the invention, a dental fixture adaptedto be inserted into a jawbone is provided. The dental fixture comprisesa component engagement portion adapted to mate with a dental component,the component engagement portion being provided with at least a firstradially projecting or indenting indexing element having a coronal end,and at least two second radially projecting or indenting indexingelements, each having a coronal end which is located coronally of thecoronal end of the first indexing element.

According to at least one example embodiment, the coronal end of thefirst indexing element is circumferentially separated from the coronalend of any one of said second indexing elements.

According to at least one example embodiment, said second indexingelements are asymmetrically distributed along the circumference of thecomponent engagement portion.

The dental fixture according to the third aspect of the invention, mayhave any one of the features of dental fixtures mentioned in connectionwith the first and second aspects of the invention and/or any one of thefeatures of dental fixtures mentioned in the following.

As mentioned above, a dental implant comprises a dental fixture and adental component.

A dental fixture is for use as the anchoring member of a dentalprosthesis. To this end, the dental fixture is insertable into apre-prepared bore hole in the bone tissue of a jawbone (maxilla ormandible) at a site where the dental prosthesis is required. The dentalfixture is normally rotated into the bore hole.

For screw-type dental fixtures the bore hole may be provided withinternal threads in advance or may be left un-tapped with the dentalfixture provided with a self-tapping capacity, e.g. by the provision ofone or more axially-extending cutting recesses, edges or notches, etc inthe fixture thread. For instance, an apical end portion of the fixturemay be provided with 2-4 cutting recesses, such as 3 cutting recesses.Other number of cutting recesses are readily conceivable.

A dental component may, as discussed previously be any one of a numberof different components. One example is a driver for inserting thedental fixture into the jawbone. Another example is a superstructure forconnecting a prosthetic part to the fixture. The superstructure maycomprise an abutment, spacer or other transmucosal component whichengages to the dental fixture to bridge the gingiva overlying themaxilla or mandible. The prosthetic part, e.g. a crown, bridge ordenture may be secured to the abutment. There are various other formsthat the superstructure can take. For instance, the prosthetic part maybe secured directly to the dental fixture.

The term “coronal” is here and throughout this application used toindicate a direction towards a head end or trailing end of the dentalimplant. For instance, in a situation where a dental abutment isconnected to a dental fixture, the coronal direction of the abutmentwould be a direction towards the part of the abutment being directedaway from the fixture. Conversely, the term “apical” indicates adirection towards an insertion or leading end of the component. Thus,apical and coronal are opposite directions. Furthermore, the terms“axial”, “axial direction” or “axially” are used throughout thisapplication to indicate a direction taken from the coronal end to theapical end, or vice versa. The terms “radial”, “radial direction” or“radially” indicate a direction perpendicular to the axial direction.

A blind bore or socket may extend apically into the fixture body fromthe coronal end to an end surface in-between the apical and coronal endsof the fixture body for a superstructure to be secured to the fixture.The socket may comprise an internally-threaded section for screwconnection of the dental component to the fixture. A rotational lock forthe dental component may be provided in the socket, such as an internalpolygonal side wall, e.g. hexagonal, or alternatively one or moreprotrusions from or indentation in the wall of the socket. A section ofthe socket, such as the coronal section, may be tapered towards theapical end. The tapered section is suitably arranged coronally of theinternally-threaded section.

The fixture may be used in a one stage procedure or a two stageprocedure. In a one stage procedure a healing or temporary abutment isconnected to the fixture to form the gingival tissue, and after ahealing period the healing or temporary abutment is replaced by apermanent abutment. For a two stage procedure the fixture is providedwith a cover screw and the gingival tissue is sutured over the fixtureand cover screw, and after a healing period the tissue is opened up andan abutment is connected to the fixture after removal of the coverscrew.

The dental fixture may have a conically tapering end portion whichtapers towards the coronal end. The axial extent of this coronal endportion is small compared to the total length of the fixture, as anexample no more than 4% of the total length, such as in the range of1.5%-3.7%. The coronal end portion may suitably be provided without athreaded surface, e.g. having a smooth or a roughened (such as blasted)surface.

The fixture may have a substantially flat coronal end surface which isperpendicular to the longitudinal axis of the fixture. Alternatively,the coronal end surface may have a sloped contour relative to thelongitudinal axis of the fixture, e.g. such that when positioned withinthe jawbone the length of the fixture is larger on a lingual side andshorter on a buccal side of the fixture. Another alternative is asaddle-shaped or wave-like coronal end surface.

The length of the dental fixture may be in the range of 5-19 mm,depending on the clinical situation. The outer diameter of the dentalfixture may suitably be in the range of 2-6 mm, such as 3-5 mm.

The fixture may be substantially cylindrical or slightly tapering fromthe coronal end towards the apical end. If the fixture has a slighttapering, the core of the fixture and the outer periphery defined bye.g. thread tops may have the same or different angle of taper.Furthermore, the core of the fixture may be cylindrical while the threadtops describe a conicity or, conversely, the core of the fixture may betapered while the thread tops describe a generally cylindrical geometry.Alternatively, the fixture may comprise a combination of one or morecylindrical and/or one or more tapering portions. Thus, one or moreportions of the fixture may have e.g. thread tops lying in a commonimaginary cylindrical surface, which cylindrical surface is parallelwith the longitudinal axis of the fixture. Alternatively oradditionally, one or more portions of the fixture may have thread topslying in an imaginary conical surface which in the apical direction istapering towards the longitudinal axis.

The externally threaded fixture may comprise one or more thread spirals.

The term “pitch” is used to indicate the axial distance between adjacenttops of a threading. The term “lead” is used to indicate the distanceadvanced parallel to the longitudinal axis when the fixture is turnedone revolution, i.e. it corresponds to the pitch multiplied with thenumber of thread spirals. For a single thread spiral having a constantpitch, the lead is equal to the pitch; for a double thread spiral, thelead is twice the pitch.

The term “microthread” is used to indicate a thread having a heightwhich is no greater than 0.2 mm. According to at least one exampleembodiment, the fixture is provided with microthreads having a height inthe range of 0.02-0.2 mm, such as 0.05-0.015 mm, for instance 0.1 mm.The term “macrothread” is used to indicate a thread having a heightwhich is greater than 0.2 mm. According to at least one exampleembodiment, the fixture is provided with macrothreads having a height inthe range of 0.25-0.35 mm, such as 0.3 mm.

Suitably, microthreads may be located coronally of macrothreads. Forinstance, microthreads may be arranged to engage dense cortical bone andmacrothreads may be arranged to engage porous spongious/cancellous bone.The lead of a microthread suitably corresponds to the lead of amacrothread. The macrothread pitch may, as an example, be 2-4 times,such as 3 times, the pitch of the microthreads. The pitch (top-to-topspacing) at a fixture portion provided with microthreads may be around0.10-0.30 mm, for instance 0.20-0.24 mm. The pitch (top-to-top spacing)at a fixture portion provided with macrothreads may be around 0.30-0.90mm, for instance 0.60-0.72 mm.

Microthreads can be regarded as defined, oriented roughness. Anon-oriented roughness having smaller dimensions, for instance obtainedby blasting, etching, etc., may be superimposed on microthreads as wellas on macrothreads.

A thread profile may comprise two flanks, a top interconnecting said twoflanks, a bottom formed between two adjacent threads, said flanksforming an acute angle v with a plane which is perpendicular to thefixture axis and which angle v lies in a plane containing the extensionof the fixture axis, said profile further having a height D. The top maybe curved and may have a top radius. Suitably, for 10°≦v≦35°, the topradius is greater than 0.4×D and, for 35°≦v≦55°, the top radius isgreater than 0.2×D.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate a dental component according to at least oneexample embodiment of the invention.

FIG. 2 illustrates a dental component according to at least one otherexample embodiment of the invention, which is to be connected to adental fixture in a specific rotational orientation with respect to thedental fixture, wherein the dental component and the dental fixturetogether represent a dental implant according to at least one exampleembodiment of the invention. FIG. 2 also illustrates another dentalcomponent which may be arranged in a number of different rotationalorientations with respect to the same dental fixture.

FIG. 2A is a top view of the dental fixture in FIG. 2.

FIGS. 2B-2C are bottom views of the dental components in FIG. 2.

FIG. 3 illustrates a fixture engagement portion of a dental componentaccording to at least one example embodiment.

FIGS. 4A-4E illustrate schematically circumferential distributions offirst and second indexing elements on dental components according todifferent example embodiments.

FIG. 5 illustrates, in accordance with at least one example embodiment,a dental component in the form of a driver to be connected to a dentalfixture.

DETAILED DESCRIPTION OF THE DRAWINGS

Each drawing illustrates a dental component having first and secondindexing elements, and some of the drawings also illustrate a dentalfixture having third and fourth indexing elements.

FIGS. 1A-1C illustrate a dental component 100 according to at least oneexample embodiment of the invention, wherein FIG. 1A is a perspectiveview, FIG. 1B is a bottom view and FIG. 1C is a partial side view. Thedental component 100 may, for instance, be an abutment, an abutmentreplica or an abutment blank. The dental component 100 comprises a bodypart 110 which is provided with a central through-hole 112, throughwhich a screw part 150 is insertable and connectible to internal threadsof a dental fixture, in order to secure the body part 110 to thefixture. The body part 110 comprises a fixture engagement portion 114,which is herein illustrated as having a generally cylindrical envelopingsurface, although other enveloping surfaces, such as tapering, would bea conceivable alternatives. The body part 110 further comprises a dentalcrown-receiving or prosthesis-receiving portion 116 which extendscoronally of the fixture above the gingiva. An extension portion 118,herein illustrated as coronally flaring up to a shoulder 120, isintended to extend through the gingiva and is provided between thefixture engagement portion 114 and the prosthesis-receiving portion 116.In case the dental component 100 is provided as an abutment blank, atleast one of the extension portion 118 and the prosthesis-receivingportion 116 may be further processed to a desired shape, which maysuitably be customized for the patient receiving the resulting processedabutment.

The fixture engagement portion 114 is provided with a radiallyprojecting first indexing element 130 having an apical end 132, and tworadially projecting second indexing elements 140 a, 140 b having apicalends 142 a, 142 b. The apical ends 142 a, 142 b of the second indexingelements 140 a, 140 b are located apically of the apical end 132 of thefirst indexing element 130. The overall axial extension of the firstindexing element 130 and the second indexing elements 140 a, 140 b issuch that the first indexing element 130 and the second indexingelements 140 a, 140 b are intersected by a common geometrical planewhich is perpendicular to the central axis of the fixture engagementportion 114. Thus, the axial extension of the first indexing element 130is at least partly overlapped by the axial extension of the secondindexing elements 140 a, 140 b.

Following the circumference of the fixture engagement portion 114, thefirst indexing element 130 is located at a position which is spaced fromthe positions of the second indexing elements 140 a, 140 b, i.e. thefirst indexing element 130 is circumferentially separated from any oneof the second indexing elements 140 a, 140 b. Expressed differently, ina cylindrical coordinate system (r, φ, z) wherein the z axis coincideswith the central geometrical axis of the engagement portion 114, theangle φ will be different for each one of the first indexing element 130and the two second indexing elements 140 a, 140 b.

The close positioning of the two second indexing elements 140 a, 140 bresults in that they are asymmetrically distributed along thecircumference of the fixture engagement portion 114. Asymmetricaldistribution means that the two second indexing elements are not evenlydistributed around the fixture engagement portion. An even, symmetricaldistribution would have the two second indexing elements distributed180° from each other around the fixture engagement portion 114.

This dental component 100 may be connected to a dental fixture havingindexing elements in the form of indexingindentations/recesses/depressions which sizewise match the indexingelements 130, 140 a, 140 b of the dental component 100. Thus, as thedental component 100 is brought into contact with the fixture, thesecond indexing elements 140 a, 140 b will be leading and will be thefirst to enter associated indexing recesses in the fixture. Once thesecond indexing elements 140 a, 140 b have mated with their associatedindexing recesses in the fixture, the trailing first indexing element130 of the dental component 100 will be substantially aligned with itsassociated indexing recess. Therefore, when the dental component 100 iscontinued to be inserted into the fixture, the first indexing elementwill easily mate with its associated indexing recess in the fixture.Thus, the leading second indexing elements 140 a, 140 b have an initialguiding/aligning function while the trailing first indexing element 130completes the rotational locking.

In FIGS. 1A-1C the indexing elements 130, 140 a, 140 b have beenconfined to a small area of the fixture engagement portion 114. Thissmall area spans over approximately 60° of the total (360°)circumference of the fixture engagement portion 114, the central(second) indexing element 140 a being spaced from its neighbours atapproximately 30°. The dental component 100 may thus mate with a fixturehaving similar distribution of indexing elements, one exemplary fixture4 being illustrated in FIG. 2. The three indexing elements or indexingrecesses of the fixture 4 in FIG. 2 which would mate the indexingelements 130, 140 a, 140 b of the dental component 100 in FIG. 1 aredenoted 30 e, 30 f, 30 g. The fixture 4 has four other indexing elements30 a-30 d, however, these are separated at a larger distance. Thus, thedental component 100 can only mate with this fixture 4 in one rotationalorientation. If one of the second indexing elements (e.g. 140 a), wouldbe aligned over an incorrect indexing element in the fixture 4, theother second indexing element (e.g. 140 b) will rest against a shelf 32in the fixture 4, thus rendering further apical movement difficult. Ifthere would have been only one second indexing element, it could havedropped into any one of the seven indexing recesses 30 a-30 g in thefixture 4, before the dentist realizes that the dental component isincorrectly orientated. Although, having two second indexing elementsstabilizes and reduces the risk of one of the second indexing elements140 a, 140 b dropping into an undesired indexing recess of the fixture,it may accidently happen if e.g. the dentist tilts the dental componenttoo much. Therefore, turning back to FIG. 10, as an optional feature thesecond indexing elements may be provided with a respective chamfer 144a, 144 b, on the side facing away from the other second indexingelement. Such a chamfer 144 a, 144 b facilitates continued rotatingmovement by the dentist in case one of the second indexing elements 140a, 140 b would slightly drop into an incorrect indexing recess. As afurther optional feature, the second indexing elements 140 a, 140 b mayhave a somewhat smaller radial or circumferential extension compared tothe first indexing element 130, in order to provide a certain play whenmating with the indexing recesses of the fixture 4. In such case, eventhough the second indexing elements 140 a, 140 b may not provide asufficient rotational lock, their underdimensioning will facilitate thelocation finding function, and the first indexing element 130 can stillbe relied upon for the rotational locking function.

It should be noted that the dental component 100 is not limited to beused with fixtures permitting only one rotational orientation. Thedental component 100 could for instance be connected to a fixture havingtwelve indexing recesses, each recess being equidistantly spaced at 30°from the neighbouring recesses. With such a fixture, the dentist mayselect any one of twelve rotational positions for the dental component100. Thus, the exemplified dental component 100 maintains thepossibility of multiple rotational positioning with some types offixtures, while providing the above-presented benefits in connectionwith fixtures permitting only a single rotational positioning.

FIG. 2 illustrates a dental component 2 according to at least one otherexample embodiment of the invention, which is to be connected to adental fixture 4 in a specific rotational orientation with respect tothe dental fixture 4, wherein the dental component 2 and the dentalfixture 4 together represent a dental implant according to at least oneexample embodiment of the invention. FIG. 2 also illustrates anotherdental component 6 which may be arranged in a number of differentrotational orientations with respect to the same dental fixture 4.

The herein illustrated dental fixture 4 has a coronal portion 8extending apically from a coronal end 12 of the fixture 4, and an apicalportion 10 extending coronally from an apical end 14 of the fixture 4.

The apical portion 10 may have a conicity tapering towards the apicalend 14 of the fixture 4 to ease insertion of the fixture 4 into abore-hole in the jawbone.

The fixture 4 has a core from which a surface structure projects, in theillustrated example being in the form of threads.

The coronal portion 8 is herein illustrated as being at least partlyprovided with microthreads 16, e.g. having three thread spirals,although another number is conceivable, such as 1, 2, 4 or more spirals.Although microthreads 16 have been illustrated, according to at least analternative example embodiment the coronal portion 8 is at least partlyprovided with macrothreads 18, similarly to the apical portion 10,either as a separate thread spiral or as a continuation of the threadspiral at the apical portion 10. According to at least anotheralternative example embodiment, instead of microthreads 16, the coronalportion may be provided with a plurality of annular ridges, which to thenaked eye could give the same visual appearance as microthreads. Otherconceivable alternatives are circumferential lines of beads ornon-oriented/randomly provided projections such as bulges.

In the illustrated example embodiment, the macrothreads 18 at the apicalportion 10 has the same lead as the microthreads 16 at the coronalportion 8. However, the pitch of the macrothreads 18 is three times thepitch of the microthreads 16, since the microthreads 16 comprise threethread spirals.

The apical portion 10 comprising macrothreads 18 is herein illustratedas having one thread spiral, however, the apical portion 10 mayalternatively have two or more thread spirals.

The length of the herein illustrated coronal portion 8 may be about 1-2mm, such as 1.5 mm. However, shorter or longer lengths are readilyconceivable. The relative length of the coronal portion 8 may also beselected from a wide range, such as 5-50% of the total length of thefixture 4, e.g. 10-20%.

The coronal portion 8 comprises a tapering end portion 20, which taperstowards the coronal end 12 of the fixture 4. The tapering end portion 20is no more than 4% of the total length of the fixture 4. The surface ofthe tapering end portion 20 may be non-threaded, either smooth orblasted (or otherwise roughened).

Cutting recesses 22 or grooves extend coronally from the apical end 14.The number of cutting recesses 22 may be one or more, such as two, threeor four cutting recesses, suitably symmetrically positioned about thecircumference of the apical end 14 of the fixture 4 for self-tapping ofthe fixture 4 when being screwed/rotated into the bore-hole provided inthe maxilla or mandible.

A socket 24 having an open end is provided in the coronal end 12 of thefixture 4. The socket 24 extends apically into the fixture 4. The socket24 is for receiving a dental component 2 such as the illustratedabutment which will bridge the gingiva overlying the bore-hole andsupport/present a prosthetic part. However, it may also receive otherdental components such as an abutment replica, a driver, a healing cap,an impression pick-up element, a digital transfer coping, etc.

Although various alternative configurations are conceivable, the socket24 is herein illustrated as having a conical coronal section 26 and asubstantially cylindrical intermediate wall section 28. Seven indexingelements 30 a-30 g, herein illustrated as radially extending recesses 30a-30 g are provided in the intermediate wall section 28 (see also FIG.2A). The intermediate wall section 28 and the radially extendingrecesses 30 a-30 g act as a component engagement portion of the fixture4. The coronal end of the intermediate wall section 28 forms a shelf 32with gaps formed by said seven recesses 30 a-30 g. Six of the recesses30 a-30 e, 30 g are equidistantly distributed along the circumference ofthe intermediate wall section 28. The seventh recess 30 f is interposedbetween two (30 e, 30 g) of said six equidistantly distributed recesses.This is clearly illustrated in the top view of FIG. 2A.

The socket 24 is further provided with an internally threaded apicalsection 34.

A dental component 2 according to at least one example embodiment of theinvention is herein illustrated as a two-piece abutment 2 consisting ofa body part 40 and a screw part 42. The body part 40 of the abutment 2is provided with a through-hole 44, wherein the screw part 42 is adaptedto be inserted into the through-hole 44 and engage the internal thread34 of the fixture 4 in order to secure the body part 40 to the fixture4. The body part 40 comprises a fixture engagement portion 46, which isherein illustrated as having a generally cylindrical enveloping surface,although other enveloping surfaces, such as tapering, would be aconceivable alternatives. The body part 40 further comprises a dentalcrown-receiving or prosthesis-receiving portion 48 which extendscoronally of the fixture 4 above the gingiva. An extension portion 50,herein illustrated as coronally flaring up to a shoulder 52, is intendedto extend through the gingiva and is provided between the fixtureengagement portion 46 and the prosthesis-receiving portion 48.

Seven indexing elements 60 a-60 g, herein illustrated as radialprojections 60 a-60 g, are provided sequentially in the circumferentialdirection of the cylindrical enveloping surface of the fixtureengagement portion 46 (see also 2B). Similarly to the distribution ofthe radial recesses 30 a-30 g in the fixture 4, there are sixequidistantly distributed radial projections 60 a-60 e, 60 g on thedental component 2, while the seventh radial projection 60 f isinterposed between two (60 e, 60 g) of said six equidistantlydistributed radial projections. With this configuration, the seventhradial projection 60 f and its two neighbouring radial projections 60 e,60 g can only mate in one correct way with the seventh radial recess 30f and its two neighbouring recesses 30 e, 30 g. Thus, there is only onerotational orientation possible for the dental component 2 to beconnected with respect to the dental fixture 4.

Four of the radial projections can be regarded as first indexingelements 60 a-60 d, each having an apical end (in FIG. 2 the apical endof the indexing element 60 d is designated with reference numeral 62 d).The other three radial projections 60 e-60 g, namely said seventh radialprojection 60 f and its two neighbouring projections 60 e, 60 g, can beregarded as second indexing elements 60 e-60 g having apical ends 62e-62 g located apically of the apical ends of the first indexingelements 60 a-60 d. This facilitates for the dentist to connect thedental component 2 to the dental fixture 4 in the correct rotationalorientation. Contrary to the example embodiment shown in FIG. 1, in thisexample embodiment the number of first indexing elements 60 a-60 d isgreater than the number of second indexing elements 60 e-60 g. In thecircumferential direction of the fixture engagement portion 46, each oneof the first indexing elements 60 a-60 d is located at a position whichis different from the positions of the second indexing elements 60 e-60g. Thus, each one of the first indexing elements 60 a-60 d iscircumferentially separated from any one of the second indexing elements60 e-60 g.

When the body part 40 of the abutment 2 is to be connected to thefixture 4, the projections forming said second indexing elements 60 e-60g may come in contact with the shelf 32 in the fixture 4. Theprojections forming said first indexing elements 60 a-60 d will still bespaced from the shelf 32. The body part 40 is then rotated so that thesecond indexing elements 60 e-60 g fall into the designated recesses 30e-30 g of the fixture 4, i.e. into the seventh recess 30 f and its twoneighbouring recesses 30 e, 30 g.

Thus, the second indexing elements 60 e-60 g will first engage with theseventh recess 30 f and its two neighbouring recesses 30 e, 30 g whichrepresent fourth indexing elements 30 e-30 g, and thereafter havingalready found the correct rotational position, the first indexingelements 60 a-60 d of the dental component 2 can engage with the thirdindexing elements 30 a-30 d (the other four recesses 30 a-30 d) of thedental fixture 4.

If only a single one (for example 60 f) of the seven indexing elements60 a-60 g of the dental component 2 would have an apical end locatedapically of the other six indexing elements, that single one (forexample 60 f) of the indexing elements 60 a-60 g could have mated withany one of the seven indexing elements 30 a-30 g of the fixture 4.However, only one (in this example 30 f) of those seven indexingelements 30 a-30 g of the fixture is the correct one which allows thetrailing indexing elements of the dental component to also mate with thecorresponding indexing elements in the fixture. If the dentist wouldplace said single one (e.g. 60 f) of the seven radially projectingindexing elements 60 a-60 g into one of the six incorrect radiallyindented indexing elements (e.g. 30 a-30 e, 30 g), the trailing indexingelements (e.g. 60 a-60 e, 60 g) of the dental component 2 would not finda mating indexing element in the fixture 4 but would abut the shelf 32.The dentist would have to lift the dental component 2 and try again tofind the correct rotational orientation of the dental component 2relative to the fixture 4. By additionally letting another one (forexample 60 g) of the seven indexing elements (60 a-60 g) have an apicalend extending apically of the apical ends of the other indexingelements, said indexing element (in this example 60 g) will be incontact with the shelf 32 of the fixture reducing the risk of the otherindexing element (in this example 60 f) falling into the incorrectrecess in the fixture 4. Thus, having a dental component with at leastone first indexing element and at least two second indexing elementshaving apical ends apically of the apical end of the first indexingelement reduces the risk of the second indexing elements falling intothe incorrect recesses in the fixture. Nevertheless, if the dentistbrings the dental component 2 towards the fixture 4 in a slightlyinclined direction, one of said second indexing elements may still beable to reach into an incorrect recess in the fixture, albeit not verydeeply because of the other second indexing element contacting the shelf32 preventing further advancement. Because the second indexing elementcannot fall deeply into an incorrect recess, a rotating motion willeasily lift the second indexing element and after continued rotation thecorrect position will be found.

Having three radially projecting second indexing elements with longerapical extensions than the trailing first indexing element furtherfacilitates correct alignment of the indexing elements of the dentalcomponent with those of the fixture. FIG. 2 illustrates an advantageousdistribution of three second indexing elements 60 e-60 g interposedbetween two (60 a, 60 d) of the first indexing elements 60 a-60 d. Themiddle one (60 f) of the second indexing elements 60 e-60 g cannot fallinto an incorrect recess (30 a-30 e, 30 g) in the fixture 4, because ofthe other two (60 e, 60 g) second indexing elements provided on eitherside thereof. When the dental component 4 is to be connected to thefixture 2, the second indexing elements 60 e-60 g will with highlikelihood land on the shelf 32, thus requiring the dentist to rotatethe dental component 4 into the correct orientation. During suchrotation, unless the dentist holds the dental component 4 absolutelystraight, one of the two outer second indexing elements (60 e, 60 g)might just slightly drop into an incorrect recess in the fixture. Sincethe drop is so small, the dentist can easily continue the rotation untilthe correct alignment is found. Nevertheless, in FIG. 3, showing afixture engagement portion 46′ of a dental component, an exampleembodiment is illustrated in which each one of the two outer secondindexing elements 60′e, 60′g are provided with a respective chamfer61′e, 61′g on the side facing away from the middle one (60′f) of thesecond indexing element. Such a chamfer 61′e, 61′g further facilitatesthe continued rotating movement by the dentist in case one of the outersecond indexing elements 60′e, 60′g would slightly drop into anincorrect recess. In FIG. 3, two shorter first indexing elements 60′a,60′d are also visible. Also, it may be noted that the apical ends of thesecond indexing elements 60′e-60′g are not flush with the apical end ofthe dental component as in FIG. 2, but instead located somewhatcoronally thereof.

As illustrated in the bottom view of FIG. 2B, the first indexingelements 60 a-60 d are somewhat wider than the second indexing elements60 e-60 g. In the dental fixture 4, however, the third and fourthindexing elements 30 a-30 g have substantially the same width. This hasthe effect that due to a larger width difference between the secondindexing elements 60 e-60 g and the fourth indexing elements 30 e-30 g,there will be a lateral play between these indexing elementsfacilitating the finding of the correct rotational orientation. In otherwords, because the radially projecting second indexing elements 60 e-60g are laterally/transversely underdimensioned with respect to theradially indenting fourth indexing elements 30 e-30 g, they will moreeasily fall into place than if they were of substantially the samedimensions. The radially projecting first indexing elements 60 a-60 dare dimensionally closer matched to the radially indenting thirdindexing elements 30 a-30 d, reducing potential lateral play, andinstead ensuring a substantially well-defined rotational position of thedental component 2 with respect to the dental fixture 4. It should beunderstood that rather than making the second indexing elements 60 e-60g narrower than the first indexing elements 60 a-60 d, an option wouldbe to make them of equal width and instead make the fourth indexingelements 30 e-30 g wider than the third indexing elements 30 a-30 d.Thus, the relatively large lateral play between the second and fourthindexing elements can be accomplished with various designs of the dentalcomponent and/or dental fixture.

In FIG. 2, the second indexing elements 60 e-60 g have been illustratedas extending all the way to the apical end of the body part 40, however,other alternatives are conceivable. For instance, the second indexingelements 60 e-60 g may extend somewhat shorter, as long as the apicalends 62 e-62 g thereof are located apically of the apical ends of thefirst indexing elements 60 a-60 d, or they may extend longer, i.e.beyond the apical end of the body part (see e.g. FIG. 3).

Furthermore, it should be noted that the coronal extension of the secondindexing elements 60 e-60 g may also be shorter. In fact, it should beunderstood that, for the radially projecting second indexing elements 60e-60 g to fall into connection with the radially indenting fourthindexing elements 30 e-30 g, the second indexing elements 60 e-60 gcould be designed as substantially flat plates projecting from thesurface of the fixture engagement portion 46 of the body part 40. Oncethe flat plates are received by the associated recesses 30 e-30 g, thewhole body part 40, including the following indexing elements 60 a-60 d(i.e. the other radial projections which have the purpose to provide arotational lock) will be guided in the desired direction for completingthe insertion of the body part 40 into the dental fixture 4.

It should also be noted that, although second indexing elements 60 e-60g have been presented in FIG. 2 as the seventh radial projection 60 fand its two neighbouring radial projections 60 e, 60 g, otheralternatives are possible. For instance, the seventh radial projection60 f and a non-neighbouring projection (such as projection 60 a, 60 b or60 c) could have their apical ends located apically of the apical endsof the other radial projections. These two radial projection would beleading and be the first ones to abut the shelf 32 provided between therecesses in the dental fixture 4. They can only fall down from the shelfwhen the seventh radial projection 60 f is aligned with the seventhradial recess 30 f. Thus, in general terms, according to at least oneexample embodiment, the distribution of the second indexing elementsaround the fixture engagement portion is asymmetrical relative to thedistribution of the first indexing elements. In other words there is atleast one pair of second indexing elements (for instance correspondingto the illustrated positions of 60 f/60 g, or 60 f/60 a, or 60 f/60 b)spaced differently than the spacing between any pair of first indexingelements.

FIG. 2 and FIG. 2C also illustrate another dental component 6 in theform of an abutment 6. It has six equally-dimensioned and equidistantlydistributed indexing elements in the form of radial projections 70.Unlike the first abutment 2, this other abutment 6 lacks a seventhprojection. Thus, this other abutment 6 may be connected to the dentalfixture 4 in six different rotational orientations.

FIGS. 4A-4E illustrate schematically circumferential distributions offirst and second indexing elements on dental components according todifferent example embodiments. Although not viewable from the drawings,in each of these example embodiments each one of the second indexingelements has an apical end located apically of the apical ends of thefirst indexing elements.

In FIG. 4A, the dental component is provided with one first indexingelement 80 and two second indexing elements 81 a, 81 b. A radius r₁ fromthe central axis to the centre of said first indexing element 80 and aradius r₂ from the central axis to the centre of one 81 a of the secondindexing elements form a first angle θ. A radius r₃ from the centralaxis to the centre of the other one 81 b of said second indexingelements and said radius r₁ from the central axis to the first indexingelement 80 form a second angle φ. The second angle φ is different fromsaid first angle θ and any angle being a multiple of said first angle θ.In other words, φ≠nθ, where n is a positive integer. The dashed lineillustrate the contour of receiving indexing elements in the fixture. Ascan be seen not all of the indexing elements in the fixture are occupiedby indexing elements of the dental component. Because of the asymmetry,the dental component can only mate in one correct rotational orientationwith the fixture.

In connection with FIG. 4A, the following should be noted. The angle θdefining the positions of the first indexing element 80 and one 81 a ofthe second indexing elements is illustrated as being 180°. Assuming adental component would be manufactured differently, with the position ofthe first indexing element 80 and the position of the other one 81 b ofthe second indexing elements being switched, then the two secondindexing elements would have been located at 180° with respect to eachother. If a dentist misplaces the dental component by 90°, the twooppositely located second indexing elements could enter receivingindexing elements in the fixture. However, the first indexing elementwould land on a shelf. When the dentist wishes to rotate the dentalcomponent to the correct position, he/she will experience a non-smooth,intermittent motion. However, the illustrated configuration in FIG. 4A,with the second indexing elements 81 a, 81 b being asymmetricallyarranged will make the location finding process much smoother. Even ifone of the second indexing elements would catch into an incorrectindexing element in the fixture, the other second indexing element willprevent it from falling too deeply, since both of the second indexingelements 81 a, 81 b have an apical end located apically of the apicalend of the first indexing element 80.

In the embodiment of FIG. 4B, an additional second indexing element 81 cis provided, compared to the embodiment in FIG. 4A. The three indexingelements 81 a-81 c makes the location finding even smoother.

In the embodiment of FIG. 4C, the dental component is provided with fivefirst indexing elements 80 a-80 e and two second indexing elements 81 a,81 b. The five first indexing elements 80 a-80 e and one 81 a of thesecond indexing elements are equidistantly arranged at 60° intervals.The other one 81 b of the second indexing elements is interposed andspaced at 30° from its neighbouring indexing elements 80 e, 81 a. Thepreviously described first angle θ will, depending on which one of thefirst indexing elements 80 a-80 e is selected as a reference point, havea value of n*60° in relation to one 81 a of second indexing elements,where n=1, 2, 3, 4, 5. In FIG. 4C the first indexing element 80 b hasbeen chosen (n=2), wherein the first angle θ=120° and the second angleφ=150°.

In the embodiment of FIG. 4D, the dental component is provided with twofirst indexing elements 80 a, 80 b and two second indexing elements 81a, 81 b. Unlike in the previous illustrations, the two second indexingelements 81 a, 81 b are not neighboring to each other in FIG. 4D. Thefirst angle θ=90° and the second angle φ=225°. Thus, the relationshipφ≠nθ is valid also for this example embodiment.

In FIG. 4E the distribution corresponds to that in FIG. 2, thus fourfirst indexing elements 80 a-80 d and three second indexing elements 81a-81 c. It is also similar to the distribution in FIG. 4C, with theexception that one of the first indexing elements has now been replacedby a second indexing element. The second indexing elements 81 a-81 chave a smaller dimension in the radial direction than the first indexingelements 80 a-80 d. Thus, when placed in a fixture having substantiallyuniformly recessed indexing elements, there will be a larger play in theradial direction between the second indexing elements 81 a-81 c and thewalls of the mating indexing element in the fixture than any play in theradial direction between the first indexing elements 80 a-80 d and thewalls of their mating indexing elements. Once the correct rotationalposition is found, the larger play facilitates insertion of the secondindexing elements 81 a-81 c into the mating recessed indexing elementsof the fixture.

FIG. 5 illustrates, in accordance with at least one example embodiment,a dental component in the form of a driver 302 to be connected to adental fixture 304. In this example, the interface between the dentalfixture 304 and the driver 302 corresponds to the interface between thedental fixture 4 and dental component 2 illustrated in FIG. 2. Thus, thedriver 304 has three radial projections (second indexing elements 360e-360 g) having an apical end 362 e-362 g located apically of the apicalends (only 362 c, 362 d shown) of the other four radial projections(first indexing elements 360 c, 360 d; only two out of four can be seenin the perspective view shown in FIG. 5). The fixture has mating thirdand fourth indexing elements, respectively (only one third indexingelement 330 b and two fourth indexing elements 330 f and 330 g can beseen in this view). Thus, similarly to the connection in FIG. 2, thedriver 302 can only be connected in one rotational orientation relativeto the fixture 304.

The driver 302 is used for rotatingly driving the fixture 304 into abore hole in the jawbone. The driver may be designed as a piece whichcan be used on its own, or alternatively, at its coronal end, the drivermay be designed to be connectible to a handle, a wrench (such as aratchet wrench), a power driver machine, etc.

The driver 302 is provided with a visually distinctive marking 380,herein illustrated as an axial line, aligned with the middle secondindexing element 360 f at the fixture engagement portion 346 of thedriver 302. The distinctive marking 380 may have a color which isdifferent from the rest of the driver 302, it may have differenttexture, or be slightly bulging, or any other appropriate viewabledistinction compared to the rest of the driver.

The driver 302 can only be positioned in a single rotational indexingposition relative to the fixture 304, meaning that each time the driver302 engages such a fixture 304, the rotational position of thedistinctive marking 380 relative to the fixture 304 will always be thesame. Thus, by viewing the axial line provided by the marking 380, auser will be able to deduce the rotational position of the fixture 304in the jawbone. This allows pre-planning and designing of the surgicaland laboratory procedure before a dental fixture 304 is even insertedinto the bone. For instance, a scan of the tooth-less site can be made,and a complete patient-specific implant may be designed in which theabutment should have a certain orientation relative to the fixture 304and relative to the surrounding tissue, and therefore the fixture 304should have a certain orientation in the jawbone.

A driver, such as the driver 302 illustrated in FIG. 5, may suitably beused with other dental fixtures. According to at least one exampleembodiment, the driver adapted to be connected to a dental fixturehaving a coronal end portion which is not flat. For instance, thefixture may have a sloped coronal end portion, in which the length ofthe fixture is greater on the lingual side than on the buccal side inorder to match the contour of the jawbone. During installation of thefixture in the jawbone, the distinctive marking of the driver willindicate to the dentist in which direction the coronal end portion ofthe fixture is sloping, thus allowing the dentist to make appropriateadjustments to correctly align the slope of the fixture with the slopeof the jawbone.

Although the drawings have illustrated dental components provided withindexing elements in the form of radial projections and dental fixtureswith indexing elements in the form of radial recesses, it should beunderstood that in other embodiments, the indexing elements of thedental components may instead be radial recesses and the indexingelements of the fixtures may be radial projections.

Furthermore, although the drawings have illustrated that the dentalcomponent as a male component having a fixture engagement portion to beinserted into a socket of the fixture (acting as a female component),other embodiments are also conceivable. For instance, the fixture mayhave a summit portion, which may suitably be adapted to extend beyondthe bone crest, and apical end of the dental component may be providedwith an socket extending coronally into the dental component, wherebythe socket is intended to be placed onto the summit portion. Radiallyprojecting or indenting indexing elements may be provided also for sucha component/fixture interface.

Although the indexing elements have been illustrated as elongate radialprojections and recesses, in other embodiments they would not beelongate. Furthermore, the cross-section of the indexing elements may beof any suitable shape, such as curved, triangular, rectangular,trapezoid, or any other regular or irregular shape.

It should also be noted that the number of indexing elements in thedental component does not necessarily have to be equal to the number ofindexing elements in the dental fixture. For instance, in FIG. 2, one ofthe radial projections forming a first indexing element could beremoved, although the effect of the rotational lock will be somewhatweakened.

1. A dental component, comprising a fixture engagement portion beingprovided with at least two radially projecting first indexing elements,each having an apical end, wherein the at least two radially projectingfirst indexing elements include a primary first indexing element and asecondary first indexing element being spaced from one another by afirst cylindrical enveloping surface portion therebetween and at leasttwo radially projecting second indexing elements being interposedbetween the primary first indexing element and the secondary firstindexing element, each one having an apical end located apically of theapical ends of said primary first indexing element and said secondaryfirst indexing element, wherein the first cylindrical enveloping surfaceportion is free of additional radially projecting first indexingelements.
 2. The dental component as claimed in claim 1, wherein said atleast two second indexing elements are asymmetrically distributed alongthe circumference of the fixture engagement portion.
 3. The dentalcomponent as claimed in claim 1, wherein said at least two radiallyprojecting first indexing elements and said at least two second indexingelements are asymmetrically distributed along the circumference of thefixture engagement portion.
 4. The dental component as claimed in claim1, wherein said at least two second indexing elements are symmetricallydistributed along the circumference of the fixture engagement portion.5. The dental component as claimed in claim 1, wherein said at least tworadially projecting first indexing elements and said at least two secondindexing elements are symmetrically distributed along the circumferenceof the fixture engagement portion.
 6. The dental component as claimed inclaim 1, wherein the axial extension of the indexing elements is suchthat the first indexing element and the second indexing elements areintersected by a common geometrical plane which is perpendicular to thecentral axis of the fixture engagement portion.
 7. The dental componentas claimed in claim 1, wherein following the circumferential directionof the fixture engagement portion, said at least two second indexingelements are interposed between two of said first indexing elements. 8.The dental component as claimed in claim 1, wherein said at least tworadially projecting second indexing elements are arranged as at leastthree radially projecting second indexing elements, interposed betweensaid at least two first indexing elements, wherein each one of saidthree second indexing elements has an apical end which is locatedapically of the apical ends of said at least two first indexingelements.
 9. The dental component as claimed in claim 1, wherein aradius from said central axis to the centre of one of said at least twosecond indexing elements and a radius from said central axis to thecentre of said first indexing element form a first angle θ, wherein aradius from said central axis to another one of said at least two secondindexing elements and said radius from said central axis to the centreof said first indexing element form a second angle φ, and wherein saidsecond angle φ is different from said first angle θ and from any anglebeing a multiple of said first angle θ, so that φ≠nθ, where n is apositive integer.
 10. The dental component as claimed in claim 1,wherein the number of first indexing elements is greater than the numberof second indexing elements.
 11. The dental component as claimed inclaim 1, wherein each one of said second indexing elements has a smallerdimension in the circumferential direction and/or in the radialdirection compared to the dimensions of said at least one first indexingelement.
 12. The dental component as claimed in claim 1, wherein said atleast one first indexing element and said at least two second indexingelements have elongate extensions in the coronal-apical direction. 13.The dental component as claimed in claim 1, wherein said at least twofirst indexing element and said at least two second indexing elementsproject radially from the first cylindrical surface portion of thefixture engagement portion.
 14. The dental component as claimed in claim1, wherein the apical end of at least one of said at least two secondindexing elements is provided with a chamfer.
 15. The dental componentas claimed in claim 1, being a component selected from the groupconsisting of an abutment, an abutment replica, an abutment blank, acustomized abutment, a scan abutment, a digital transfer coping, animpression pick-up element, a healing cap and a driver.
 16. A dentalimplant, comprising a dental component comprising a fixture engagementportion provided with at least two radially projecting first indexingelements, each having an apical end, wherein the at least two radiallyprojecting first indexing elements include a primary first indexingelement and a secondary first indexing element being spaced from oneanother by a first cylindrical enveloping surface portion therebetween,and at least two radially projecting second indexing elements beingcircumferentially spaced from one another and interposedcircumferentially in the first groove cylindrical enveloping surfaceportion and between the primary first indexing element and the secondaryfirst indexing element, each one of the second indexing elements havingan apical end located further apically relative to the apical ends ofthe primary first indexing element and the secondary first indexingelement, wherein the first cylindrical enveloping surface portion isfree of additional radially projecting first indexing elements, a dentalfixture adapted to be inserted into a jawbone and comprising a componentengagement portion adapted to mate with said fixture engagement portion,the component engagement portion being provided with at least two thirdindexing elements, each one having a coronal end, and at least twofourth indexing elements, each one having a coronal end, wherein theapical ends of said at least two second indexing element are locatedapically of the apical end of the at least two first indexing elementand/or the coronal ends of said at least two fourth indexing elementsare located coronally of the coronal end of the at least two thirdindexing elements, wherein the first, second, third and fourth indexingelements are distributed along the circumference of the fixtureengagement portion and the component engagement portion, respectively,in such way that the dental component can only mate in one rotationalorientation with respect to the dental fixture, and wherein the at leasttwo first indexing elements are only enabled to mate with the at leasttwo third indexing elements after said at least two second indexingelements have mated with said at least two fourth indexing elements. 17.The dental implant as claimed in claim 16, wherein a play between the atleast two first indexing elements and the mating at least two thirdindexing elements is smaller than a play between said at least twosecond indexing elements and said at least two mating fourth indexingelements, whereby a tighter fit is provided between the at least twofirst and at least two third indexing elements compared to the fitbetween the second and fourth indexing elements.
 18. The dental implantas claimed in claim 16, wherein said first and second indexing elementsare provided as radial projections which project from a surface of thefixture engagement portion of the dental component, and wherein saidthird and fourth indexing elements are provided as radial depressions ina surface of the component engagement portion of the dental fixture. 19.The dental implant as claimed in claim 16, wherein said at least twosecond indexing elements are symmetrically distributed along thecircumference of the fixture engagement portion, and wherein said atleast two fourth indexing elements are symmetrically distributed alongthe circumference of the component engagement portion.
 20. The dentalimplant as claimed in claim 16, wherein said at least two secondindexing elements are asymmetrically distributed along the circumferenceof the fixture engagement portion, and wherein said at least two fourthindexing elements are asymmetrically distributed along the circumferenceof the component engagement portion.
 21. The dental implant as claimedin claim 16, wherein a radius from a central axis of the fixtureengagement portion to the centre of one of said at least two secondindexing elements and a radius from said central axis to the centre ofone of said at least two first indexing elements form a first angle θ,wherein a radius from said central axis to another one of said at leasttwo second indexing elements and said radius from said central axis tothe centre of one of said at least two first indexing element form asecond angle φ, and wherein said second angle φ is different from saidfirst angle θ and from any angle being a multiple of said first angle θ,so that φ≠nθ, where n is a positive integer.
 22. The dental implant asclaimed in claim 16, wherein the fixture engagement portion and thefirst and second indexing elements of the dental component are rotatableinside the component engagement portion of the fixture before the secondindexing elements have mated the fourth indexing elements.
 23. A dentalfixture comprising a component engagement portion being provided with atleast two first radially projecting or indenting indexing element havinga coronal end, wherein the at least two radially projecting or indentingfirst indexing elements include a primary first indexing element and asecondary first indexing element being spaced from one another by afirst cylindrical enveloping surface portion therebetween, and at leasttwo second radially projecting or indenting indexing elements beinginterposed between the primary first indexing element and the secondaryfirst indexing element, each one having a coronal end which is locatedcoronally of the coronal end of the primary first indexing element andthe secondary first indexing element, wherein the first cylindricalenveloping surface portion is free of additional radially projectingfirst indexing elements.
 24. The dental fixture of claim 23, wherein thedental fixture is adapted to be inserted into a jawbone.
 25. The dentalcomponent as claimed in claim 23, wherein said at least two secondindexing elements are asymmetrically distributed along the circumferenceof the component engagement portion.
 26. The dental component as claimedin claim 23, wherein said at least two first indexing elements and saidat least two second indexing elements are asymmetrically distributedalong the circumference of the component engagement portion.
 27. Thedental component as claimed in claim 23, wherein said at least twosecond indexing elements are symmetrically distributed along thecircumference of the component engagement portion.
 28. The dentalcomponent as claimed in claim 23, wherein said at least two firstindexing elements and said at least two second indexing elements aresymmetrically distributed along the circumference of the componentengagement portion.